Boosting a L92
Thread Starter
Teching In
Joined: Dec 2024
Posts: 18
Likes: 3
Boosting a L92 I have a L92 that I'm looking to do at max 12lbs of boost through, I intend on running the stock bottom end with E85. Is gaping my rings or whatever needed with a mild street build pushing probably 550-600hp?
I think you'd fine, trouble is when using E85 you can run way more than 12 lbs. which most end up doing.
I'd at least check the ring gaps and adjust for the day when 12 lbs. just isn't enough anymore.
I'd at least check the ring gaps and adjust for the day when 12 lbs. just isn't enough anymore.
There is no way to know for sure if it will be safe on any amount of boost. The factory tolerance variations in ring gap can be enough to blow up on any additional power, or be fine with much more than that. That being said, I'm sure everyone on this section of the forum has taken their chances with boosting an unopened factory motor (I sure as hell have), but with the knowledge that having unmeasured build specs always carries the risk of a big boom. The tuneup will also have a lot to do with it, as well as how long you plan to run at full load, since the total amount of heat is what eventually butts ring lands. You can get away with a hell of a lot more power for 1/8 mile pulls than for extended top speed runs.
Thread Starter
Teching In
Joined: Dec 2024
Posts: 18
Likes: 3
There is no way to know for sure if it will be safe on any amount of boost. The factory tolerance variations in ring gap can be enough to blow up on any additional power, or be fine with much more than that. That being said, I'm sure everyone on this section of the forum has taken their chances with boosting an unopened factory motor (I sure as hell have), but with the knowledge that having unmeasured build specs always carries the risk of a big boom. The tuneup will also have a lot to do with it, as well as how long you plan to run at full load, since the total amount of heat is what eventually butts ring lands. You can get away with a hell of a lot more power for 1/8 mile pulls than for extended top speed runs.
Personally I would just run it and make sure the tune is spot-on. Once you take off the oil pan, "feature creep" balloons the cost of whatever your original simple plan may have been. Next thing you know you have an expensive motor that can still be killed with an overboost or bad tune situation.
Thread Starter
Teching In
Joined: Dec 2024
Posts: 18
Likes: 3
Personally I would just run it and make sure the tune is spot-on. Once you take off the oil pan, "feature creep" balloons the cost of whatever your original simple plan may have been. Next thing you know you have an expensive motor that can still be killed with an overboost or bad tune situation.
So, I don't know what you paid for that L92 but that's not an engine that I would just roll the dice with like a junkyard 4.8 or 5.3.
If it were me, even with 200K miles I'd at least check the ring gaps and clean up the piston ring lands, a feeler gauge is all that's needed to check, visually check the cam bearings and throw some factory spec bearings in it if they look worn.
No special tools needed, and no crazy rebuild required.
Those L92 blocks go for $2K alone so I'd do a little preventative stuff for sure.
Melling HV oil pump, ARP head studs, turbo cam, BTR .660 drop in springs, push rods and have at it.
What size turbo are you considering?
Trending Topics
Thread Starter
Teching In
Joined: Dec 2024
Posts: 18
Likes: 3
Engines w/ 200K miles on them typically have pretty wide gaps as a rule.
So, I don't know what you paid for that L92 but that's not an engine that I would just roll the dice with like a junkyard 4.8 or 5.3.
If it were me, even with 200K miles I'd at least check the ring gaps and clean up the piston ring lands, a feeler gauge is all that's needed to check, visually check the cam bearings and throw some factory spec bearings in it if they look worn.
No special tools needed, and no crazy rebuild required.
Those L92 blocks go for $2K alone so I'd do a little preventative stuff for sure.
Melling HV oil pump, ARP head studs, turbo cam, BTR .660 drop in springs, push rods and have at it.
What size turbo are you considering?
So, I don't know what you paid for that L92 but that's not an engine that I would just roll the dice with like a junkyard 4.8 or 5.3.
If it were me, even with 200K miles I'd at least check the ring gaps and clean up the piston ring lands, a feeler gauge is all that's needed to check, visually check the cam bearings and throw some factory spec bearings in it if they look worn.
No special tools needed, and no crazy rebuild required.
Those L92 blocks go for $2K alone so I'd do a little preventative stuff for sure.
Melling HV oil pump, ARP head studs, turbo cam, BTR .660 drop in springs, push rods and have at it.
What size turbo are you considering?
I'll probably take it to the machine shop to have all the bearings replaced and cleaned as I do not trust myself buying the equipment and doing it all right
I imagine E85 is really the only way to go with this much boost and 10.5:1 compression
as for what size turbo I am running a 12k mile supercharger off a hellcat I paid $1600 for
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
That will be cool! Who's kit did you buy to put the supercharger on it? E would be the best fuel to run, but there's several variables involved. How are you going to control the valve in it?
Thread Starter
Teching In
Joined: Dec 2024
Posts: 18
Likes: 3
I have not bought any of the supercharger parts yet, only stuff to rebuild the entire engine basically
I plan on buying from Trinity Performance they have adapter plates for rectangle & Cathedral, hellcat griptec pulleys that are offset for the LSA, (although I'm ordering mine with a truck offset) and throttle body adapter, wish we could run the OEM hellcat throttle body not exactly sure what the electrical differences are that make them not work as I'd rather not drop $350 on a throttle body and LS adapter
Then I have a LSA 8 rib front drive kit for the trucks from Olson Kustom Work
Smoothboost sells a standalone controller for the bypass valve which wires into your pedal and has a input/dial to control the max boost
I'm too cheap to drop money on a forged bottom end(going to be nearly 25k into this engine swap) so E85 is probably my only other option which with the stock 600cc injectors on the hellcat should max me around 600hp which is way more than enough for me, I'll probably destroy my axles or trans with 37" tires and 600+ hp
And as for the ECU it came factory with a E67 which I'll be mating a 6l80e to, I could run a CTS-V OS with a 2 bar map? I'm not familiar with those things at all, I'm not sure what the benefit of having a higher bar map or whatever.
I plan on buying from Trinity Performance they have adapter plates for rectangle & Cathedral, hellcat griptec pulleys that are offset for the LSA, (although I'm ordering mine with a truck offset) and throttle body adapter, wish we could run the OEM hellcat throttle body not exactly sure what the electrical differences are that make them not work as I'd rather not drop $350 on a throttle body and LS adapter
Then I have a LSA 8 rib front drive kit for the trucks from Olson Kustom Work
Smoothboost sells a standalone controller for the bypass valve which wires into your pedal and has a input/dial to control the max boost
I'm too cheap to drop money on a forged bottom end(going to be nearly 25k into this engine swap) so E85 is probably my only other option which with the stock 600cc injectors on the hellcat should max me around 600hp which is way more than enough for me, I'll probably destroy my axles or trans with 37" tires and 600+ hp
And as for the ECU it came factory with a E67 which I'll be mating a 6l80e to, I could run a CTS-V OS with a 2 bar map? I'm not familiar with those things at all, I'm not sure what the benefit of having a higher bar map or whatever.
Last edited by MrBlod; May 19, 2025 at 11:21 PM.
I have not bought any of the supercharger parts yet, only stuff to rebuild the entire engine basically
I plan on buying from Trinity Performance they have adapter plates for rectangle & Cathedral, hellcat griptec pulleys that are offset for the LSA, (although I'm ordering mine with a truck offset) and throttle body adapter, wish we could run the OEM hellcat throttle body not exactly sure what the electrical differences are that make them not work as I'd rather not drop $350 on a throttle body and LS adapter
Then I have a LSA 8 rib front drive kit for the trucks from Olson Kustom Work
Smoothboost sells a standalone controller for the bypass valve which wires into your pedal and has a input/dial to control the max boost
I'm too cheap to drop money on a forged bottom end(going to be nearly 25k into this engine swap) so E85 is probably my only other option which with the stock 600cc injectors on the hellcat should max me around 600hp which is way more than enough for me, I'll probably destroy my axles or trans with 37" tires and 600+ hp
And as for the ECU it came factory with a E67 which I'll be mating a 6l80e to, I could run a CTS-V OS with a 2 bar map? I'm not familiar with those things at all, I'm not sure what the benefit of having a higher bar map or whatever.
I plan on buying from Trinity Performance they have adapter plates for rectangle & Cathedral, hellcat griptec pulleys that are offset for the LSA, (although I'm ordering mine with a truck offset) and throttle body adapter, wish we could run the OEM hellcat throttle body not exactly sure what the electrical differences are that make them not work as I'd rather not drop $350 on a throttle body and LS adapter
Then I have a LSA 8 rib front drive kit for the trucks from Olson Kustom Work
Smoothboost sells a standalone controller for the bypass valve which wires into your pedal and has a input/dial to control the max boost
I'm too cheap to drop money on a forged bottom end(going to be nearly 25k into this engine swap) so E85 is probably my only other option which with the stock 600cc injectors on the hellcat should max me around 600hp which is way more than enough for me, I'll probably destroy my axles or trans with 37" tires and 600+ hp
And as for the ECU it came factory with a E67 which I'll be mating a 6l80e to, I could run a CTS-V OS with a 2 bar map? I'm not familiar with those things at all, I'm not sure what the benefit of having a higher bar map or whatever.
Save your money and leave the stock bottom end in it.
The 6L80E is a good trans, get an aftermarket converter for it because the factory ones are a bit sketchy, the one in my 2015 Silverado failed at 100K miles with no abuse or towing.
Definitely run E85 if you have it, its all around a better fuel than pump gas.
You'll be roasting those 37" tires my friend with a six-speed auto and PD blower lol.
I had a 77 Chev. Short Box 4x4 on 35's with a warmed over 454 BBC and it would boil the tires from a stop, it was great lol.
Nothing like seeing the back of a square body swaying from one side of the lane to the other while leaving thick black strips on the pavement.
Thread Starter
Teching In
Joined: Dec 2024
Posts: 18
Likes: 3
I'd go for 35's but all the 35's out there are heavier or weigh the same as some of the 37s, but the 37s will certainly fit the wheel wells better.
I'll be running a NP149 AWD T-case so hopefully theres no roasting of anything, I do have a D60 rear end and a D44 front end out of a rubicon. I wonder how many axles I'll go through on the D44
I'll be running a NP149 AWD T-case so hopefully theres no roasting of anything, I do have a D60 rear end and a D44 front end out of a rubicon. I wonder how many axles I'll go through on the D44
I'd go for 35's but all the 35's out there are heavier or weigh the same as some of the 37s, but the 37s will certainly fit the wheel wells better.
I'll be running a NP149 AWD T-case so hopefully theres no roasting of anything, I do have a D60 rear end and a D44 front end out of a rubicon. I wonder how many axles I'll go through on the D44
I'll be running a NP149 AWD T-case so hopefully theres no roasting of anything, I do have a D60 rear end and a D44 front end out of a rubicon. I wonder how many axles I'll go through on the D44
A 6.2 with a Hellcat blower is gonna easily make 600hp, I'm betting you'll be closer to 800hp honestly.
Hopefully you'll select a nice choppy blower cam to go with it.
Thread Starter
Teching In
Joined: Dec 2024
Posts: 18
Likes: 3
I bought a donor vehicle for 4k that has literally everything I need plus more to sell off. I already had the L92 laying around and I decided I wanted even more power than the L92 had to offer by going with cam and ported heads from TSP for $1800, but that much power requires a upgraded front diff and I'm sure not putting nearly 500hp into a 7.6" ring gear IFS setup so I bought a D44 and D60 brand new 0 miles for rubicon for $4000. Then people on the lowbuck LS facebook group then proceeded to convince me to go boosted so now here I am. I no longer need the donor vehicle so if anyone wants to buy a functioning wrecked H3 Alpha with 180k miles for $4000 you know who to ask
This will be by far the fastest vehicle I've ever owned, I thought my factory v8 colorado was fast when I bought it
Just be careful with the extra power. There is a thread in the gen4 internal section called "403 NA build" that should serve as a cautionary tale of too many power mods and not enough driver mod. Forced induction can be far worse.
Took the buyer for a ride and demonstrated how violent the car could be in the first three gears, which admittedly probably helped sell the car.
Told him to be extremely careful and the minute you don't respect the power; it will bite you directly on the *** with this car, I even turned the boost down to 10 lbs. after the ride/sale.
A month or so later I see a video on his Facebook page of the car completely wadded up.
He was making a hit in the early morning when the roads were cold, grabbed third, lost control and spun it out into the highway median and bashed every side of the car.
OP that blower is gonna hit like a hammer, take it slow and be careful my friend, don't want you to become another cautionary tale.
Do you have pics of the build you can share because it sounds pretty cool.
@gametech just read it, bro was on a dirt road in a C6 Grand Sport getting after it......wtf was he thinking man.